1. Field of the Invention
The present invention relates to an off-road tire for motorcycle in which a plurality of blocks are disposed on a treat portion.
2. Description of the Related Art
As shown in FIG. 7, in an off-road tire for motorcycle in which a plurality of blocks (b) are disposed on a tread portion (a), in order to enhance the cornering performance on the off-road, it is desired that an axially inner block edge (bie) of a shoulder block b1 is provided axially outward of the tire. This is because that the edge effect of the inner block edge (bie) largely contributes to the lateral grip performance at the time of cornering. As the inner block edge (bie) of the shoulder block (b) is provided more axially outward of the tire, the lateral edge effect is more enhanced, and even when a tire is banked at a larger camber angle, the lateral slip can be suppressed and the cornering speed can be increased.
However, when the shoulder block (b1) is provided outward in the axial direction of the tire, the tread width (tire width) is naturally increased. As a result, the running performance when running on the off-road is deteriorated, and interference between the tire and a swing arm which supports the tire through a rim, and/or between the tire and driving chain may happen. Also, when the inner block edge (bie) of the shoulder block b1 is shifted outward in the axial direction of the tire while maintaining the tread width, there is a problem that the block width of the shoulder block b1 is reduced and it causes chipping and/or damage to the shoulder block.